Thermodynamic and Heat Transfer Performance of the Organic Triangle Cycle

Compared to the organic Rankine cycle (ORC), the organic triangle cycle (TC) is simpler in structure and is not limited by pinch point temperature differences. TC has been studied to some extent by previous researchers, such as the selection of working fluid, application, and the design of the expander. However, system optimization and parameter analysis of TC are still rare. The thermodynamic performance of TC internal circulation and TC heat recovery systems are investigated by theoretical analysis and numerical simulation, respectively. The results indicate that the expander inlet temperature T3 and heater inlet temperature T2 are key elements impacting the thermodynamic performance of the TC internal circulation. For the TC heat recovery system, an optimal value of the average heat-capacity flow rate of working fluid Cwf is discovered to output the maximum net power output Wnet. Moreover, the total heat transfer coefficients for the heater (kA)h and condenser (kA)c are discussed in relation to Cwf variations. The findings will provide critical guidance for system investment and optimization.